Single-purpose fertilisers of the “chemical” type as listed above are relatively pure chemicals, and because of hostility to life such as non-neutral pH, osmotic effects or others, life forms are substantially absent from these fertilisers as sold. There has been no particular reason to modify these fertilisers with micro-organisms. It may follow that application of at least some of these materials to the ground also brings at least short-term hostility to soil micro-organisms as well. The very low pH of superphosphate (rock phosphate treated with sulphuric acid) is one form of hostility.
For many years it has been known that some animals, or some plants, show poor thrift or restricted growth and it has been found in many cases that addition of small amounts of certain elements (many of which are in the group known as “trace elements” to the soil (or sometimes directly to the animals or plants) can overcome the problems. Boron, copper, manganese and zinc deficiencies all reduce plant dry matter and plant vigour.
Examples include: (1) Plants with yellowish leaves. In some cases this is caused by a deficiency of magnesium which is a component of the green photosynthesis protein/enzyme called chlorophyll. (2) Animals (bovines) with poor condition and a particular type of anaemia particularly if living on lands which were covered by ash showers, pumice, etc in recent eruptions in the centre of the North Island of New Zealand. These have been shown to be significantly deficient in cobalt. Similarly, copper deficiency, selenium deficiency, and many other types of deficiency in one or more elements are known. (Occasionally a deficiency to the end-user arises because of antagonism between two elements, such as copper and molybdenum, and occasionally toxic effects occur because of excessive amounts of for example copper or selenium). That such deficiencies may arise is not surprising if the total pool for a given material is limited and farmers consistently ship out plant or animal material that includes some of the pool.
There is therefore a well-developed practice of taking soil, plant or animal samples, subjecting them to appropriate chemical analysis, and providing remedial amounts of specific elements if incorrect amounts are reported, within fertilisers or in other more direct ways.
Sometimes the remedial amounts of elements (such as copper, commonly administered at about 12 kg per hectare as copper sulphate) are in themselves toxic to soil micro-organisms. Copper salts are known as a means to kill algae even at concentrations of 1 part in 40,000. In a test, copper sulphate at an amount corresponding to 1 kg/ha killed the algae in a turbid swimming pool in a few hours.
Use of soluble salts (such as copper; zinc, or cobalt sulphate) has the risk that the salts may be washed away from the sites on which they are broadcast before the micro-organisms can include them in their biomass. Clearly it would be an advantage for a user of fertiliser that any added trace elements are released from the applied fertiliser in a slow manner so that they are present for a long period (such as 12 months), whereas addition of simple salts (such as copper sulphate) that are highly soluble relies on such as adsorbtion effects against soil particles to hold the copper ions in place.
The inventor has previously supplied chelated micro-elements incorporated within a fish nutrient hydrolysate for direct application on to the ground. Although these are an improvement over inorganic salts, it has been noted that these chelates can be leached away fairly easily.
The inventor desires to invent and make fertilisers which can be broadcast without significant harm to the micro-organisms in the soil, wherein the nutrients in the fertiliser can be absorbed by at least some of the soil micro-organisms as part of their nutrients, while the trace elements which are mainly already incorporated within added micro-organisms as part of the cell structure remain in the upper layers as an enrichment, exchanged between micro-organisms, and made available to plants and then to animals.